This invention relates to a gas cylinder and electrical switch combination, and particularly such a combination which sets the switch function parameter on the initial operation of the gas cylinder.
Gas cylinders are commonly used on vehicle liftgates and lift windows, some of which are referred to as hatchbacks, as well as on a variety of other items such as furniture, office machines, etc. When used on such assemblies, particularly automotive equipment, it is sometimes desirable to electrically activate a light or other device when the cylinder is operated. A good example of this is the actuation of a dome light in a vehicle when the gas cylinder is extended by opening the liftgate/lift window. It has been known heretofore to provide an electric switch mounted on the cylinder so that the switch is actuated by the cylinder with opening of the liftgate/lift window. Specifically, the affiliated German company of the assignee herein has manufactured and sold pneumatic cylinder-electrical switch combination units for use on automobiles as early as 1978. However, there has existed a problem in assuring actuation of the switch with opening of the liftgate/lift window. Conceivably, this problem could also exist on other equipment. This problem has been found to be due to the "buildout tolerance" involved. Specifically, when a vehicle is assembled from many components, each connection or subassembly has a tolerance range. When these ranges are accumulated for several connections, the total variance between components such as the liftgate/lift window and the adjacent body structure can be as much as three-eighths or even one-half inch. Hence, while the electrical switch may function effectively in some vehicles off the assembly line, it might not function properly in others because of the failure of electrical contacts to compensate for the different amounts of cylinder movement.